A conventional ultrasonic probe applied in a field of examining a subject using ultrasonic has been disclosed, for example, in Japanese Patent Application Laid-Open Publication No. 2003-500955 (Patent Document 1). The invention or device disclosed in the Publication comprising a supporting member, a gap, an insulating film, an upper electrode, and a protective film disposed on a silicon substrate whose resistance has been reduced by doping. In the device, an insulator of silicon nitride, which is the supporting member, is formed and a lid of silicon nitride for closing a gap between the same and the insulator is formed on the insulator. Ultrasonic is transmitted and received by applying an electric signal between the upper electrode and the silicon substrate to vibrate the membrane above the gap.